Open nightgryphon opened 3 years ago
I have similar problem, I have CNC screen to replace, 18.3khz h-sync, 50hz v-sync. I get right half of the screen cut off. TV5275 is poorly documented and changing output res to something useful for me(1024x768) took a day of hex editing. If there is profile generator it's not known to duckduckgo nor google. all i got is register description PDF and programming manual, which isn't the greatest help. now I'm stuck on input shifting. I have some black empty on the left and right edge cut off. No matter how I try to move it in web GUI I get green garbage on the right. Signal works perfect on borrowed CRT and looks ok on oscilloscope - video signal is not overlapping h-sync polarities are correct.
There is a serial command parser in the code. You send it characters and it does them. You can use this to quickly set the main parameters of a preset, such as the number of lines, and it'll figure out what to configure to get them. Example: "wvt 1066" means "write vertical total 1066", which would produce enough lines for an x1024 preset. Here is the parser, sadly undocumented (I wrote it for myself :p) https://github.com/ramapcsx2/gbs-control/blob/master/gbs-control.ino#L8230
You also need to google how to read modelines, then use a modeline list (https://www.mythtv.org/wiki/Modeline_Database#VESA_ModePool) to find some main parameters of presets. Your x768 preset would use 806 total lines, for example (wvt 806)
How can i build and upload custom preset in case i can record the exact sync signal with logic analizer and measure any part of this signal? I have problems with GBS Control on some retro PC like "УКНЦ МС 0511" and some others. There is no or unstable picture. But i see the sync is valid and both TV and old tube monitor can recognize it. Can i manually create the required preset when GBS auto detect fails?
Here is the example SYNC graph captured with logic analyzer at the output of video processor before mixing